Cable trays are used extensively in the construction industry for running the various cables used in a building along certain predetermined paths. Cable trays may, for example, be suspended from a ceiling or mounted to walls so that the various wires and cables used in the building may be laid therein for a more orderly and accessible placement. Typically, a particular construction project requires a variety of cable trays of different shapes and sizes to accommodate the particular layout for the cable tray system. Because each project may require its own unique variety of cable trays, there is no generally accepted or standard shipping configuration or load-out for cable trays.
Due to the lack of a standard method of packaging cable a cable tray for shipment, cable trays are typically shipped in bundles having a matrix of one or more rows of cable trays stacked one on top of the other. Cable trays may also be arranged so that pairs of cable trays are interwoven in facing engagement and the pairs then stacked in a number of rows and columns. Further, bundles of cable trays may include cable trays having a variety of shapes and sizes. Each bundle is typically wound only with shipping straps. These bundles of cable trays can therefore be very difficult to handle without damaging the cable trays. Often, damage to a bundle of cable trays occurs because the bundles get dragged, pushed or pulled during the various transfers among shipping or storage trailers.
The use of pallets to ease the handling and transferring of bulk packages is well known. A pallet typically provides cargo with vertical separation from the ground so that a forklift or crane may lift the entire bundle all at once. A pallet can also provide containment of the cargo itself. One drawback of pallets, once constructed, is that until they are utilized with cargo they tend to take up valuable warehouse space. Also, once used, the pallets are often not returned or reused in the packaging or shipping of another item. As a result, the construction and storage of pallets adds costs for both the shippers and receivers. It is therefore desirable that palletizing units have low construction costs and provide easy storage.
Packaging pallets are known in the prior art.
U.S. Pat. No. 2,526,228 to Hammer discloses a packaging used to palletize a stack of flat sheets or panels. Two rows of longitudinally and transversely aligned skids are each stapled to a strap used to bind the stack. The stack is then placed or built on top of the skids so that the skids are centered underneath. The longitudinal straps are then bound around the stack to hold the skids thereto. Additional straps are then cinched transversely around the stack between each of the transversely aligned skids to further secure the stack. Such packaging, however, does not account for a stack of articles in matrix form as may be encountered with cable trays. Should the stack consist of more longitudinal rows than provided by the spacers, an interior row of cable trays could slide free of the pallet. Furthermore, the Hammer patent does not provide for the longitudinal engagement of a palletized stack that is more than twice as long as the tines of the forklift.
U.S. Pat. No. 4,317,517 to Tisdale discloses a palletizing assembly for a stack of flat sheets or panels utilizing two-piece spacers. Each spacer is formed from a length of laminated paper having an M-shape being inserted into a length of laminated paper having a U-shape. The stack is placed or built on top of a plurality of so-formed spacers. The spacers lie so that the bottom of the U-shaped piece engages the stack while the single groove presented by the M-shaped piece lies along the ground. A strap is run along the groove of each spacer and cinched around the stack. The pallet formed in this manner, however, fails to engage and secure any articles lying in the interior of a matrix stack such as may be found with bundled cable trays. The Tisdale patent also fails to provide a pallet which may be longitudinally engaged by the tines of a forklift.
It is therefore desirable to provide a palletizing package for a matrix stack of cable trays that longitudinally restrains each cable tray in the stack while also allowing engagement of the palletized stack from the transverse and longitudinal direction by the tines of a forklift.